package com.hmdp.service.impl;

import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.SimpleRedisLock;
import com.hmdp.utils.UserHolder;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.web.servlet.LocaleResolver;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.util.ArrayList;
import java.util.Collections;
import java.util.concurrent.*;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService iSeckillVoucherService;

    @Resource
    private RedisIdWorker redisIdWorker;

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private RedissonClient redissonClient;

    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }

    private BlockingQueue<VoucherOrder> orderTasks =new ArrayBlockingQueue<>(1024*1024);
    private static final ExecutorService SECKILL_ORDER_EXECUTOR= Executors.newSingleThreadExecutor();


    @PostConstruct
    private void init(){
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }

    private class VoucherOrderHandler implements Runnable{

        @Override
        public void run() {

            while (true){
                //获取队列信息
                try {
                    VoucherOrder voucherOrder = orderTasks.take();
                    handlerVoucherOrder(voucherOrder);
                } catch (InterruptedException e) {
                    log.error("处理订单异常");
                }

                //创建订单
            }
        }

    }
    private IVoucherOrderService proxy;

    private void handlerVoucherOrder(VoucherOrder voucherOrder) {
        Long userId = voucherOrder.getUserId();
        RLock lock= redissonClient.getLock("lock:order:" + userId);

        boolean islock = lock.tryLock();
        if(!islock){
            log.error("不允许重复下单");
            return ;
        }
        try {
            proxy.createVoucherOrder(voucherOrder);
        }finally {
            lock.unlock();
        }
    }

    /**
     * 枪秒杀券
     * @param voucherId
     * @return
     */
    public Result seckillVoucher(Long voucherId) throws InterruptedException {
       //执行lua脚本
        UserDTO user = UserHolder.getUser();
        Long userId = user.getId();
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(), user.getId().toString()
        );

        //结果是否为0
        int r = result.intValue();

        //不为0
        if(r!=0){
          return Result.fail(r==1? "库存不足" :"不能重复下单");
        }

       //为0

        VoucherOrder voucherOrder = new VoucherOrder();
        long orderId = redisIdWorker.nextId("order");
        voucherOrder.setId(orderId);

        voucherOrder.setUserId(userId);
        voucherOrder.setVoucherId(voucherId);
       //下单信息保存到阻塞队列中
       orderTasks.add(voucherOrder);
        //获取代理对象
        proxy=(IVoucherOrderService) AopContext.currentProxy();

        //返回订单id
        return Result.ok(orderId);
    }

    @Transactional
    public  void createVoucherOrder(VoucherOrder voucherOrder) {
        Long userId = voucherOrder.getUserId();
        Long voucherId = voucherOrder.getVoucherId();
        // 检查是否已经购买过
        Integer count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();
        if (count > 0) {
            log.error("用户已经购买一次了");
            return;
        }
            //是，扣库存
            boolean sucess = iSeckillVoucherService.
                    update()
                    .setSql("stock = stock -1")
                    .eq("voucher_id", voucherId)
                    .gt("stock", 0)
                    .update();
            if (!sucess) {
                log.error("库存不足");
                return ;
            }
            //log.error("如数据库订单扣减，应看到此提示");

            //，抢单成功

            save(voucherOrder);
        }
}
